Desensitization of cyclotrimethylenetrinitramine with dinitroethylbenzene



DESENSITIZATION F CYCLOTRlll/IETHYLENE- ZEIRINITRAMINE WIlH DINIT'ROEI'HYLBEN- The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to desensitization of high explosives. More particularly it relates to desensitizing granular high explosives by coating with dinitroethylbenzene.

Densitization of explosives has long been a problem of major concern to persons working in the field of explosives. Since explosives must of necessity be made and used by humans, they must primarily be safe to handle. Quite often, desirable explosives do not possess this quality and must be modified to make them less sensitive.

Cyclotrimethylenetrinitramine, hereinafter designated as RDX, is one such explosive. Despite its excellent explosive characteristics, its military use has often been restricted by its high sensitivity.

In order to overcome this defect, the conventional practice has been to coat the crystalline grains of RDX with an inert material, usually micro-crystalline wax or other suitable equivalent. While this procedure generally achieved a significant measure of desensitization, it usually resulted in a large number of crystals not being coated adequately or properly. A further disadvantage is that this desensitization has been obtained at the expense of explosive power, since for a given weight of explosive charge, a definite weight of inert material is used to replace the explosive.

Since coating with wax has decided limitations, the use of dinitroethyl-benzene, hereinafter designated as DNEB, offers a new approach to the solution of the sensitivity problem. Because of its unique properties as liquid explosive with extremely low sensitivity, it can be easily used to coat a granular material fairly evenly. At the same time it cannot be initiated until the RDX is detonated. In this manner it not only contributes to the desensitization, but also contributes to the explosive power.

Accordingly it is an object of the instant invention to desensitize explosives and thereby facilitate safe handling thereof.

It is a further object to provide a method for uniformly coating granular explosives rendering them desensitized.

By coating the RDX or other granular explosive with DNEB the impact sensitivity and the friction sensitivity are greatly improved. DNEB has the advantages of (1) not detracting but actually contributing to the explosive effect, and (2) desensitizing the high explosive so that it can be shipped and handled without being water-wet.

A specific example of coating RDX with DNEB is as follows: Sixty pounds of water is poured into a 40-gallon stainless steel kettle equipped with an air-driven propellernited States Patent 0 "ice type agitator which has for example, 'four inch'blades on a one and one-half inch shaft. The agitator is started and twenty pounds of RDX is slowly sprinkled into the kettle. In a separate operation, a small quantity of Alox 600 wetting agent is dispersed in three pounds of DNEB, the small quantity of Alox being of magnitude of two-hundredths of a pound. As described in chemical dictionaries, an Alox compound is mixed oxygenated hydrocarbons derived from the controlled partial oxidation of petroleum fractions ranging from the boiling point of gasoline to micro-crystalline waxes. They consist fundamentally of mixtures of organic acids and their esters ranging from C to C and higher. The properties of Alex 600 are, specific gravity at 158 F., 0.81 16 to 0.9042 and viscosity, Saybolt, 240-290 at 210 F.

This separately prepared mixture described above is then poured into the RDX water slurry, while the latter is being agitated. Mixing is then continued for fifteen minutes at the expiration of which the material in the kettle is then filtered on a vacuum pan through a closeweave cotton twill cloth. The product, coated RDX, is then dried in a circulating forced-air dryer at approximately 60 C.

In accordance with the above process the following table indicates representative proportions that may be used in preparing batches:

The ratio of RDX to water is arbitrary. Any convenient proportion that results in good mixing and a minimum loss of DNEB is satisfactory.

Wetting agents other than Alox 600 may be used. For example, sorbitantrioleate can be used in the same quantities as Alox. It is also our discovery that desensitization can be achieved without using any wetting agent at all, but best results are obtained with Alox 600 and its use is preferred by us.

From the foregoing, it is apparent to those skilled in the art, that our invention comprises not only the new product, desensitized high explosives, but the process or method of producing the same. It is further apparent that as a result of the present invention, substantially improved desensitization is possible for granular explosives such as trinitrotoluene, cyclotetramethylenetetranitramine, tetryl, pentaerythrite tetranitrate, etc. Also, whether the DNEB is dispersed into the kettle in solution with a suitable wetting agent or separately, it will be recognized by those skilled in the art that variations are within the spirit of this invention and accordingly the above disclosure is considered merely as illustrative and not as limitat-ive.

What we claim is:

The method of desensitizing granular cyclotrimethylenetrinitramine by coating which comprises the steps of (a) preparing a slurry .by pouring slowly twenty pounds of cyclotrimethylene-trinitramine into a kettle with water while the water is being agitated, (b) preparing a separate mixture by pouring approximately two hundredths of a pound of a wetting agent comprising an oxygenated hydrocarbon consisting fundamentally of mixtures of organic acids and their esters having from five to thirty- 5 five carbon atoms in the chain, into three to five pounds of dinitroethylbenzene, (c) pouring the mixture into the slurry while the slurry is being agitated until thoroughly mixed, (d) filtering the said product through a closeweave cotton cloth, and (e) drying the filtered product 1 by circulating air of approximately 60 C. therethrough.

References Cited in tie file of this patent UNITED STATES PATENTS I-I-ale June 18, 1935 Fassnacht et a1. a Apr. 17, 1951 OTHER REFERENCES Bebie: Manual of Explosives, Military Pyrotechnics, and Chemical Warfare Agents, 1943, pages 60-61. 

